Overall use of public transit in the Twin Cities was at its highest level in more than three decades, with more riders than ever opting for light rail. But figures released by Metro Transit indicated that fewer people took the bus last year.

The transit agency reported Friday that ridership on buses, the Green and Blue light-rail lines, and the Northstar commuter rail edged upward by 1.4 percent to nearly 86 million rides in 2015. That’s the highest level since 1981.

“We’ve really turned a corner when it comes to transit in the Twin Cities,” Metro Transit General Manager Brian Lamb said in a statement.

The star performer of transit last year was the Blue Line light rail, which connects Target Field in downtown Minneapolis to the Mall of America. The line set a ridership record with 10.6 million rides, the highest since the line opened in 2004. That’s about an 11.9 percent increase over the 9.5 million rides provided in 2014.

But overall bus ridership slumped by 8.6 percent, “reflecting a transition from buses to light rail and construction that led to prolonged detours on multiple routes,” Metro Transit said.

The transit agency, a division of the Metropolitan Council, said efforts to boost bus ridership will continue in 2016 with the opening of the region’s first arterial bus-rapid transit line on Snelling Avenue in St. Paul this spring, new bus stop signs, more shelters and a new mobile app.

“With two light-rail lines, more than 100 bus routes and a commuter rail line, the Twin Cities is more connected than it’s been in a very long time,” Lamb said.

Ridership on the Green Line light rail was about 12.4 million last year, compared with 6.5 million in 2014 — the line opened in June 2014. Average weekday ridership on the line, linking the downtowns of Minneapolis and St. Paul through the University of Minnesota, was 37,400 — just under the 2030 forecast of 41,000, Metro Transit said.

The Northstar commuter line, linking Minneapolis to Big Lake, saw an increase of 1,423 rides in 2015 to 722,637. It was unclear Friday whether Northstar is performing to expectations.

Metro Transit spokesman Howie Padilla said the agency is still reviewing the numbers to assess transit trends. He did note that Metro Transit began installing automatic passenger counters on trains last year to track passenger boardings. These overhead sensors inside the train measure movement into and out of light-rail cars, and are more efficient than recording ridership manually.

Metro Transit’s report also noted that 55 percent of its customers pay their fares with a Go-To card or some other “automatic fare product.” And 575,348 rides were provided to and from the State Fair in St. Paul, the highest express and regular route ridership ever.

Transportation reporter Janet Moore covers trains, planes, automobiles, buses, bikes and pedestrians. Moore has been with the Star Tribune for 21 years, previously covering business news, including the retail, medical device and commercial real estate industries.